Carburetor device



1941- R. L. DICKSON 2258o03 CARBURETOR DEVICE 7 Filed Jan. 1'7, 1940 5Sheets-Sheet l 1 i7 INVENTOR.

ROBERT L. .DICKSON BY W Mb,

ATTORNEY.

Filed Jan. 17, 1940 5 Sheets-Shet 4 INVENIOR.

ROBERT L. .D/CKSON BY ATTORNEY.

Patented Oct. 7, 1941 UNITED STATES PATENT OFFICE CARBUBETOB DEVICERobert L. Dickson, Sacramento, Calm, assignor to 31%? as": 5.312353;titsitht Application January 17, 1940, Serial No. 314,243

21' Claims.

This invention relates to carburetors.

An object of this invention is to provide a carburetor wherein the gasis expanded to a predetermined pressure and is fed so as to maintainsaid predetermined pressure constant, and from which the expanded gas isdischarged by a sensitive control responsive to the operation of theengine.

An object of this invention is to provide a carburetor in which thesupply of fuel into the carburetor as well as the discharge of the fueland the discharge from the carburetor is regulated by suction from anengine to which said from the carburetor are positively controlled andregulated so as to maintain a predetermined supply through saidcarburetor.

Another object of this invention is to provide a carburetor-wherein thefuel is expanded in the presence of heat so that a predeterminedconstant pressure is maintained for the supply of such expanded fuel toa usual mixing chamber or the like.

Another object of this invention is to provide a carburetor wherein thefuel is expanded in the presence of heatin an expansion chamber and thefuel intake is regulated by a mechanism controlled by the expandedpressure of the fuel, and the discharge from which expansion chamber iscontrolled by the suction of the engine.

Another object of this invention is to provide a novel and eflicientexpansion device for carburetors, and particularly to provide a highlyefficient heat exchanger for carburetors in which the fuel is contactedwith a large heating surface a carburetor for fuel, such as butane,liquefied petroleum gas, natural gas, or other gases of comparativelylow boiling point, wherein the fuel is pre-expanded to a predeterminedpressure,

and fed to the engine through devices positively controlled by theengine so as to tightly shut off the feed when the engine is inoperativebut to be sensitive to the slightest idling operation of seconddiaphragm so that said control autowithin a comparatively limited spaceof an expansion chamber.

Another object of this invention is-to provide a novel mechanism forcontrolling the feed of the fuel to the carburetor so as to maintain apredetermined gas pressure in the carburetor.

Another object of this invention is to provide a positive fuel dischargemechanism for carburetors which is sensitively controlled by suctionfrom the engine and which provides for idling discharge as well as forpositive shutting off of the gas flow from the carburetor when for anyreason the engine is stopped or the control is out of order.

Another object of this invention is to provide a method of carburetionfor gas wherein the gas is expanded to a predetermined pressure in thepresence of heat, the gas beingintroduced to and withdrawn from saidheat exchange at the hottest point of the carburetor, and wherematicallycloses the discharge valve and prevents the discharge of fuel when thesuction at the diaphragm is broken for any reason.

Another object of this invention is to provide a carburetor in whichhighly volatile fuel or fuel of low boiling point and the like is fed tothe carburetor under high pressure, is expanded and reduced to apredetermined lower pressure in said carburetor and is completelyconfined in said carburetor and positively held against escapement bysaid predetermined pressure and by sensitive balanced dischargemechanisms actuated'by engine suction for controlling the discharge.

Other objects of this invention are to provide a carburetor method anddevice that will be superior in point of simplicity, safety,inexpensiveness of construction, positiveness of operation, facility andconvenience in use and general efiiciency.

Other objects of the invention together with the foregoing will be setforth in the following description of the preferred method and thepreferred embodiment of means for practicing the same, which isillustrated in the drawings accompanying and forming part of thespecificain the introduction of the gas into the carburetor tion. It isto be understood that I do not limit myself to the embodiment disclosedin said description and the drawings as I may adopt variations of mypreferred forms within the scope of my invention.

With the foregoing and other objects in view,

which will be made manifest in the following detailed description,reference is had to the accompanying drawings for the illustrativeembodiment of the invention, wherein:

Fig. 1 is a front view of the carburetor.

Fig. 2 is a sectional view of the carburetor, the secticrn being takenon the line 2-4 of Fig. 1, also showing diagrammatically the connectionto the mixer.

Fig. 3 is a sectional view of the carburetor so as to show the heatexchanger in its expansion chamber. m

Fig. 4 is a front view'of the carburetor partly broken away to show theshut-oil! diaphragm control, and the intake control chamber.

Fig. 5 is a sectional view of the carburetor, showing the intake controland expansion control regulator, the section being taken on the lines5-5 of Fig. 4.

Fig. 6 is a fragmental sectional view of the discharge regulator infullyopened position.

Fig. '7 is a fragmental sectional view of the discharge regulator infully closed or shut-oi! position;

Fig. ,8 is a sectional view of the discharge regulator in idlingposition, and

Fig. 9 is a fragmental, sectional detail view, showing the relativearrangement of the spray orifices on the nozzle tube of the heatexchanger device.

In-general the method of carburetion in accordance withmy inventionincludes the steps of expanding the fuel in the presence of heat,maintaining a predetermined constant pressure of the expanded fuel bycontrolling the fuel intake by the expanded pressure so as'to keep thefuel intake closed until the expanded pressur falls below apredetermined pressure. and regulating the discharge of the expandedfuelfrom the carburetor by the suction of the engine on which thecarburetor is used.

The first step, namely the expanding of the also acts as a safetymeasure in preventing the building up of dangerous pressure in theexpansion chamber of the carburetor.

The third step, namelythe' discharge regulation according to enginesuction, is accomplished in two steps. First the discharge of theexpanded fuel from the carburetor is entirely and automatically shuto'fi whenever the engine suction deos not operate the dischargeregulating mechanism. Upon the starting of the engine and while it isidling the dischargemechanism is unlocked and kept opened to a presetopening by the action of the manifold suction of the engine. Secondlythe released discharge mechanism is then regulated by the action of thesuction at th mixing chamber of the carburetor leading to said engine.This permits a positive opening for idling of the engine, a flexiblecontrol through the usual throttle valve, and the automatic shutting offof the fuel discharge whenever the discharge regulator is not responsiveto engine suction.

In the herein illustration is shown an embodiment of my invention in atype of carburetor particularly adapted for use in connection with gasesof low boiling point. For instance butane gas is provided in liquid formin pressure tanks and it must be expanded to a suitable lower pressure,such as'to about ten pounds pressure, in order to be used in gas form.The various novel features of my device are capable of different uses inthe regulation of fuel feed for combustion.

In the herein embodiment of my device in general I make use of anexpanding device A, an intake control mechanism B and a dischargeregulating device C.

The expanding device A includes a heat exchanger II and a multiple sprayor nozzle tube It above'the heat exchanger ll, both disposed in anexpansion chamber I3 and both being covered by a shield ll. Theexpansion chamber II is comparatively fiat and extends over the surfaceat many points. In addition the fuel is so circulated that the fuelunder pressure is introduced into the carburetor at about the placewhere the heating medium for the heating element enters and is thehottest. The expanded fuel is also returned through a secondary path toabout said hottest portion of the carburetor when the expanded gas ispassed toward the discharge orifice of the carburetor.

Thesecond step, namely the maintaining of a constant predeterminedexpanded pressure, is accomplished by the provision of an intake controlmechanism which closes the fuel intake of the carburetor by the directapplication of the expanded pressure against a predetermined yieldableopening force so as to keep the intake closed at all times while theexpanded pressure is sufiicient to overcome said yieldable openingforce.

when the expanded pressure becomes lower than the yieldable openingforce then the latter acts to open the intake and admit additional fuelto be expanded until the pressure is again built up to close the intake.This step maintains a substantially constant pressure and base I of thecasing I! on which latter all the herein devices and mechanisms aresupported. The heat exchanger II is formed into a coillike conduitthrough which a heating medium, such as hot water, is passed. The heatex changer II is made of a plurality of parallel tubes II the ends ofwhich are mounted in head boxes I Q and II. Each head box is divided bytransverse partitions 22 into separate head spaces each of whichcommunicates the adjacent ends of two of the tubes It. The series ofpartitions 22 of the oppositehead boxes I 9 and 2| are so staggeredrelatively to each other that the respective opposite heads overlap andconnect the tubes ll into one continuous conduit with tubes ll formingturns of the conduit consecutively in opposite directions. An inlet 23is detachably connected into the end of the first or top turn of theheat exchanger H and an outlet is detachably connected to the lower endturn of said heat exchanger II. It is to be noted that the connections23 and 24 are insertable from the outside of the expansion chamber It.The heat exchanger I I is firmly held in the chamber It by set screws 26extended from the outside of the chamber I3 into engagement with thehead box 2| so as to coact with securing nuts 21 of the intake 23 and ofthe outlet 24 for holding the heat exchanger H in place. The bottom ofthe expansion chamber II is covered by a removable cover 28 so that theheat exchanger II and parts of the heat exchanger device may be removedfrom the expansion chamber 3. The heating medium, such as hot water,circulates from the inlet 23 through the turns formed by the tubes l8and the partitioned head boxes l9 and 2| to and out through the outlet24, thereby exposing a large heating surface in the comparatively smallchamber l3.

The nozzle tube 2 is made of a perforated tube insertable through a hole29 in the side wall of the chamber l3 and seated in a socket 3| oppositesaid hole 29. The outer end 32 of the nozzle tube I2 is closed and it isthreaded or otherwise adapted to be secured in place. The nozzle tube I2is extended parallel with and above the first turn or top tube |8 oftheheat exchanger II and has a series of nozzles or jets 33 whichgradually increase in size toward the closed end 32 so that the fuel isintroduced in substantially equalized sprays over the top .ofthe? heatexchanger I I. The fuel is fed'into the open end of the nozzle tube |2from the socket 3| and from an intake passage 34. It is to be noted thatthe intakegpassage 34 and the-open end of the nozzle tube 2 are adjacentto the inlet 23 of the heat exchanger II which is the warmest part ofthe expansion chamber l3. In this manner the fuel is heated in itspassage to the nozzles and the subsequent heat exchange is, renderedstill more efficient.

The shield 4 is closed at its top and sides and extends over the nozzletube 2 and over the heat exchanger so as to leave a'space 36 betweeneach of its sides and the adjacent wall of the chamber l3. The shield I4is open at its bottom end 31. This arrangement of the shield |4 confinesthe path of the fuel from the nozzles 33 to the surfaces of the heatexchanger I and thereby causes the-fuel spray to impinge upon the manyexposed heating surfaces of the heat exchanger and be expanded before itleaves the primary path of the fuel within the shield l4. The fuel thusexpanded is forced then to continue on a secondary heat exchanger pathname:- ly through the spaces 36 between the sides of the shield I4 andthe walls of the. expansion chamber |3 upwardly to the hotter upper partof said chamber 3, and during this secondary path the gas or vaporcontacts the warmed walls of the shield |4.

The intake control mechanism 13 is located in a separate valve chamber38 formed integral with the casing l1 and is offset as shown in Fig. 5so as to be adjacent and partly in extension of the wall 39 containingthe intake passage 34. The wall 39 is the heated wall and it extends toform a part of the wall of the valve chamber 38. In the extension of thewall 39 is securedfrom the outside an intake connection 4| from a usualfuel tank. A protruding intake part 42 on the end of theconnection 4| islocated at an angle to the intake passage 34 so as to feed the fuel intosaid intake passage 34 when the intake port 42 is uncovered. A hole 43extends through the extension of the wall 39 in continuation of theconnection 4| and into the valve chamber 38. Into this hole 43 slidablyfits a valve rod 44 which extends across the valve chamber 38 in aninclined position in axial alignment with the intake port 42. The tailend of the valve rod 44 is guided in asocket 46 in the wall 41 of thevalve chamber 38. The valve end of the valve rod 44 is recessed and inthe recess thereof is secured a compressible valve seat fitting over theprotruding orifice of the intake port 42.

The intake valve rod 44 is reciprocated by a diaphragm 48 held by acover 49 across the top of the valve chamber 38. A bell crank 5| ispivoted at one end to-a lug 52 on the underside of the diaphragm 49 andat its comer to a stay 53 fixed in the wall 41. The position of the bellcrank 5| is such that its free end 54 fits into a suitable slot in thevalve rod 44 and moves the valve rod 44 toward the intake port 42 whenthe diaphragm 48 is urged outwardly of the valve chamber 38, and ismoved away from the valve port 42 whenthe diaphragm 48 is moved inwardlyof the valve chamber 38. A spring 56 in the cover 49 normally forces thediaphragm 48 inwardly of the valve chamber 38 so as to urge the valverod 44 into valve opening position. This spring 56 is ofapredeterminedtension so as to overcome a definite pressure in the valvechamber 38. The spring is such that it will be held compressed, and thediaphragm thus held in the valve closing position, by the constantpressure to which the fuel is to be expanded in the heat exchangerdevice A. Whenever the ex-. panded gas pressure falls below said desiredpressure the spring will move the diaphragm 48 inwardly of the valvechamber 38 and move the valve rod 44 so as to uncover the intake port42. Thus the fuel under pressure will be introduced into the intakepassage 34 and into the heat exchanger device A as heretofore described.When sufficient fuel is expanded to create the desired pressure then thediaphragm is moved outwardly of the valve chamber 38 against the actionof the spring 56 and the intake port 42 is again closed. The valvechamber '38 partly overlaps the front wall of'the expansion chamber |3near the top and a hole 51 through said wall, as shown in Fig. 4,transmits expanded gas from the top of the expansion chamber |3 into thevalve chamber 38 so that the diaphragm 48 is actuated by the pressure ofthe gas expanded by the heat exchanger device A.

The discharge regulating device C includes a diaphragm actuated valvemechanism. On the front part of the top of the expansion chamber 3 is aseparate discharge valve chamber 58 which receives the expanded gasthrough a discharge passage 59 shown in Fig. 2. The discharge valvechamber 53 has vertically aligned threaded openings 6| and 62 into whichis threadedly secured a valve cage 63 held in place by an outsidelocknut 64. The valve cage 63 has apertures 66 around a portion of itsside walls through which the expanded gas passes from the dischargevalve chamber 58 to the interior of the valvecage 63. On the end of thevalve cage 63 in the inner opening 6| is an outwardly extended sharp rimforming a discharge orifice or discharge port 61 which communicateswith. the apertures 66 through the inner cavity 68 of the valve .cage63. The valve cage 63 is hollow throughout its entire length.

A valve 69 is opposite the discharge port 61 and has in itrecessed acompressible seat H for sealing engagement with the mouth of thedischarge port 61. From one side of the valve 69 extends a spring cup 12which also serves as an alignment guide in a spring socket 13 formed inthe front of the casing H. A spring 14 in the spring socket urges thevalve toward the discharge port 61. Into the other face of the valve 69is threaded a valve stem 16, a flange of which holds the compressibleseat H in place. This valve stem 16 extends axially into the cavity 68of the valve cage 63. Above the valve cage cavity 68-the passage throughthe valve cage 88 is narrower and it guides another spring cup 'I'I'from which extends an extension stem 18. In the second spring cup 11 andaround the extension stem I8 is another spring I8 which as its other endbears against a bushing 8| adjustably threaded into the outer end of thevalve cage 88. The relative forces exerted by the springs I8 and I8 aresuch that the inner spring I8 is capable to move the valve II intoclosed position, seat it over the discharge port 81 and hold the valvein closed position in such a manner that in said closed position theclosing spring I8 is substantially balanced by the outer spring I8 andby the normal expanded gas pressure issuing'from the heat exchangerdevice A. To achieve such substantial balance the tension of the outerspring I8 may be adjusted by the bushing 8I.

For the idling of the engine, when the suction in the usual mixingchamber is not sufficient to open the valve, a positive valve openingdevice is provided at the outer end of the valve cage 88. A screw plug81 isadiustably threaded into the bushing 8I. The screw plug is hollowand has therein a slidable plunger 88. A reduced plunger abutment 88protrudes from the plunger 88 through a small hole 88 in the bottom ofthe plug 82. A spring 81 in the screw plug .82 urges the plunger "towardthe end of the extension stem 18 of the valve 88. The length of theextension stem vI8 is such that in the closed positionof the valve 88 itpushes up the plunger abutment 84.

In this manner the force of the phmger spring 81 is transmitted to theextension valve stem I8 so as to offset the force of the closing springll to an adjusted degree and keep the valve slightly open for idling.The extent of valve opening for idling can be adjusted by adlusting theposition of the screw plug 82 in the bushing 8| and in the'valve cage88. The outer end of the valve cage 88 has a cap 88 threaded thereon toprotect these valve adjustments.

The discharge valve 88 is regulated and controlled by diaphragmsactuated by the suction of the engine on which the carburetors are used.A discharge regulating diaphragm 88 is mounted in a diaphragm controlchamber 8|, the bottom 82 of which latter is the front wall of theexpansion chamber I8. The discharge regulating diaphragm 88 is held inplace on a ledge 88 by a securing and spacing ring 88. An air vent 88between the wall 82 and the diaphragm 88 releases back pressure andassures free action of the diaphragm 88. A lever 88 is pivoted at oneend thereof to 9. lug 81 of said diaphragm 88. The lever 88 is extendedthrough a large opening 88. in the ring and in the side of the chamberadjacent the discharge valve 88 and has its outer end bent and forked soas to form a yoke 88 fitting over a neck groove III at the base of thevalve 68. The lever 88 is fulcrumed at I82 on ears I88 near its bend orcorner so that when the discharge regulating diaphragm 88 is movedtoward the lever 88 then the latter moves the valve 88 away from thedischarge port 81 and when said diaphragm 88 is not subjected to suctionthen the outer or closing spring I8, is permitted to move the valve 88back toward the discharge port 81.

The suction for the operation of the discharge regulating diaphragm 88is created at the usual 7 mixing chamber I88 of a usual carburetor, thefuel line I88 of which is connected through a replaceable Venturi outletill to an outlet space I88 into which the fuel is discharged'from theinto said outlet space I88 so that the mixingsuctionisalsoexertedonthedlaphragm". This auction depends on the degreeof opening of the throttle valve I88 but it is lower than the manifoldsuction between the throttle valve I88 and the engine. Thus thedischarge of the expanded gastoandthroughthemixingchamber iillisregulated and controlled in amanner quickly responsive to the throttlevalve adjustments.

When the engine stops entirely then the aforesaid idling opening must beclosed by an automatic shut-oi! mechanism. For thlspurpose aso-calledlockingdiaphragmlflisdisposedinthe diaphragm control chamber 8Iand is held in parallel spaced relationto the regulating diaphragm 88between a front cover III and the top of the spacing ring 88. Thelocking diaphragm I I I separates the chamber under the dished coverIII. A locking abutment II8 on'the locking diaphragm III abuts againstthe h1g8! on the regulating diaphragm. A spring Ill in the center of thecover II! bears against the center of the locking diaphragm III so as tourge the locking abutment II8 against the lug 8.1 and against the end ofthe lever 88 so as to positively force the discharge valve 88 intoclosed position and firmly lock it against opening. The space in thedished cover II! is connected by a conduit II8.to the engineat apointpast the throttle valve.l88 wasto subjectthe outside face of thelocking diaphragm I I I substantially to the manifold suction. Themanifold suction is much higher and exerts more suction force than thesuction in the mixing chamber I88. Therefore as soon as the engine isstarted; the manifold suction quickly pulls the locking diaphragm IIIout of locking position, and holds this locking diaphragm I I I ininoperative positionvas long as the engine is in operation. This permitsthe opening of the discharge valve 88 for idling and its regulationthereafter through the lever 88 and the regulating diaphragm 88 and bythe suction in the mixing chamber I88 of the carburetor. If the enginestops, or the locking diaphragm I I I for some reason is out of orderand does not react to suetion, the spring Ill automatically shuts offthe gas supply and podtively prevents the flooding of the carburetor.

When the gas is shut-off at the discharge port 81, the pressur .in theexpanding mechanism shuts-off the intake also and prevents excessivepressure in thedevice.

The device is simple and unitary in character. The expansion chamber l8functions as a base which is covered at its front by the diaphragmcontrol chamber 8I, and carries at its top, or at its heated end boththe intake control chamber 88, and the separate discharge chamber 58,with an outlet I 81 in front of the discharge chamber 88. The mixingchamber may be directly mounted on the outlet I81 or the device may beconnected by the flexible line I88 to a usual carburetor mixing chamberI88.

It is to be understood that while the features in the hereinillustrative embodiment are described as parts of a carburetor, certainof the novel features herein may be used on fuel vaporizerg or fuelexpander devices for different purposes so as to render the combustionof gases discharge port 81. The opening 88 also opens chamber throughwhich the fuel is passed in said carburetor; of aheat exchanger in saidchamber comprising, a conduit extended through said chamber and carryinga heating medium, means to introduce said fuel into the chamber and oversaid conduit, and a shield spaced from the chamber walls and extendedover the said fuel introducing means and over said conduit so as toconfine a primary fuel path around the surface of said conduit, and asecondary path for the ex-.

panded fuel in the space between the shield and the chamber walls.

2. In a carburetor the combination with a chamber through which the fuelis passed in said carburetor; of a heat exchanger in said chambercomprising, a conduit formed substantially in the shape of a coil andcontaining a heating medium, a spray conduit extended along said conduitfor introducing a fuel, a shield fitting over said spray conduit andsaid coifto direct the primarypassage of the fuel over the turns of saidcoil, said shield being 'open' adjacent the last turn of the coil, andbeing spaced from. the wall of said chamber so as to provide a secondarypassage for the fuel, an outlet from said expansion chamher outside ofthe closed end of the shield, and means adjacent said outlet to controlthe intake of the fuel into said spray conduit.

3. A heat exchanger for fuel gas, comprising an expansion chamber, anintake nozzle to conduct the fuel gas into said chamber, means extendedover said nozzle in spaced relation to the walls of the chamber so as todivide the chem.- ber into a primary path and a secondary path whereinthe gases pass successively in opposite directions the primary pathleading away from said nozzles, and a heating element with a tortuousheating surface positioned in the primary path of the fuel.

4. In a carburetor, the combination with a heat exchanger for expandingthe fuel andmeans to introduce the fuel to the heat exchanger; of anadjustable intak mechanism. between the fuel introducing means and thefuel supply, means acted upon by a predetermined expanded fuel pressurefrom said heat exchanger to keep said intake mechanism closed, and meansoperating only at expanded pressures lower than said predeterminedpressur so as to open said intake mechanism.

5. A control mechanism for fuel intake comprising, an intake port, avalve to cover the intake port, a pressure chamber adapted to receivefuel under pressure, means in said pressure chamber to normally urge thevalve into intake opening position, means actuated by the pressure insaid chamber to hold said urging means in valve closing positionwhenever the pressure in said chamber is at or above a predeterminedpressure and to release said opening at other times, and means tointroduce expanded fuel under pressure into said pressure chamberindependently of the intake valve for controlling the intake valveposition.

6. An intake control for a carburetor having an expanding means for thefuel, of a separate control chamber, an intake port outside said chamberleading to said expanding means, a valve slidably extended through awall of the chamber to cover said port, a diaphragm in said chamberbeing actuated by the pressure in said chamber, means of connectionbetween the diaphragm and the valve to close said valve when thediaphragm is held under predetermined pressure in the chamber and toopen said valve when said predetermined pressure, and means to conductexpanded fuel from said expanding means into said chamber.

7.'In a carburetor, an expansion chamber, a heat exchanger mechanism insaid chamber, means to.introduce the fuel to said heat exchanger means,a pressure regulator chamber communicating with the expansion chamber soas to have equalized pressure in both chambers, a pressure actuatedmechanism in said pressure regulator chamber, a closure elementconnected to said pressure actuated mechanism and extended through thewall of said pressure regulator chamber to the intakeof said fuel introducing means so as to close and open said intake in accordance with thepositions of said pressure actuated mechanism, said pressure actuatedmechanism being adiustable to be held in intake closing position by apredetermined pressure in said chamber, andmeans to move said pressureactuated mechanism to intake closing position when the pressure in saidregulator chamber is below said predetermined pressure. v

8. In a carburetor, the combination with the expansion chamber of thecarburetor and the means to convey the fuel to the expansion chamber, ofa separate chamber containing the same the pressure in said chamber isreduced below pressure as that of the expanded gases in the expansionchamber, an intake in a wall and outside of the separate chamber leadingto said fuel conveying means, a slidable valve member in the separatechamber extended into the wall of the separate chamber to cover saidintake, a

diaphragm in the separate chamber, means to' urge the diaphragm into thespace of the separate chamber by a predetermined force, said diaphragmbeing so located in said separate chamber that the gas pressure in saidseparate chamber counteracts said urging means at said predeterminedpressure, and means of connection between said valve member and saiddiaphragm to hold said valve member in intake closing position when thepressure in said separat chamber is suiiicient to resist said urgingmeans.

9. In a pressure regulator for carburetors, a fuel expansion means forthe carburetor, a separate fuel intake regulator chamber, a fuel passageleading in a wall and outside of said regulator chamber into saidexpansion means, a valve member slidably guided within said chamber andinto said wall so as to obstruct said fuel passage in closed position, adiaphragm in said regulator chamber, resilient means to hold saiddiaphragm at a predetermined tension against the pressure in saidchamber, a connection between said diaphragm and said valve member tohold the valve member in passage obstructing position until the pressurein said regulator chamber is insufl'icient -to counteract thepredetermined tension of said resilient means.

10. A discharge mechanism for a gas carburetor, comprising a dischargeorifice, a valve for covering said orifice, resilient means to hold saidvalve seated on the-orifice in a substantially balanced closingposition, resilient means to unbalance said first resilient means so asto keep the valve open to a predetermined discharge opening, and meansto automatically seat said valve against the action of said secondresilient means when the engine is not running.

11. A discharge mechanism fora carburetor, comprising a dischargeorifice, a valve adapted to be seated on said orifice, a diaphragmactuated lever to regulate the moving of said valve away from theorifice, means to connect said diaphragm to the suction action of thecarburetor mixing chamber, means to force the lever into valve closingposition, and a second diaphragm actuated by the manifold suction of theengine to relieve the valve closing action of said forcing means fromsaid lever when the engine is runmug.

12. A discharge mechanism for carburetors, comprising a dischargeorifice, avalve for the discharge orifice, a diaphragm actuated by thesuction of the carburetor mixing chamber, means of connection betweenthe valve and the diaphragm for opening said valve in accordance withthe suction in said mixing chamber, means to hold the diaphragm and saidmeans of connection in valve closing position, and suction actuatedmeans to release said holding means when the engine is in operation. 13.In a carburetor, a fuel -a valve to cover said orifice, and means tocontrol said valve. comprising, a pair of spaced diaphragms," the spacebetween the diaphragms communicating with the suction of the mixingchamber of the carburetor, the first diaphragm,

being adapted to be actuated by the suction in the mixing chamber, meansof connection between said first diaphragm and the valve for opening thevalve by said suction, the second diaphragm being connected to themanifold suction of the engine so as to be actuated thereby, means tonormally force the first diaphragm into valve closing position, andmeans of connection between said forcing means and the second diaphragmto release said forcing means from the first diaphragm when the seconddiaphragm reacts to a manifold suction.

14. In a carburetor, means to discharge fuel to the mixing chamber ofthe carburetor, a valve to control the fuel discharge, and a valvecontrol mechanism comprising, a pair of spaced diaphragms, the spacebetween the diaphragms communicating with the suction in the mixingchamber, means connecting one of said diaphragms to said valve so as toopen the valve when the diaphragm is subjected to said mixing chambersuction, yieldable means exerting on the first diaphragm a locking forcegreater than and opposite to the force of the suction on said firstdiaphragm soas to hold the first diaphragm in valve closing position,the second diaphragm being so related to said yieldable means as toovercome its locking force when subjected to suction, and means tosubject said second diaphragm to manifold suction of the engine so as torelease the force of said yieldable means from said first diaphragm.

15. A valve control for anism of carburetor, comprising, a pair ofspaced diaphragms in the same chamber, the space be-' tween thediaphragms communicating with the discharge suction of the carburetormixing chamber, a lever extended from said space to connect one of thediaphragms to the discharge mechanism so as to control the dischargefrom said discharge mechanism, means exerting a yieldable force on saiddiaphragms so as to hold said first diaphragm and said lever in a dis:charge closing position, and means to conduct the force of the manifoldsuction to the outside of the second diaphragm so as to release saidyieldable force from the first diaphragm and allow opening of thedischarge mechanism.

16. A discharge mechanism for carburetors comprising a casing secured inthe discharge chamber, a discharge orifice on said casing, a

fuel discharge mechvalve for engagement with said orifice, means tosupport the valve in a substantially balanced closed position, a valvestem extended from said valve axially into said casin an abutment holderadjustably secured into said casing, an abutmeans and hold the valveopen to an opening determined by the position of said abutment.

17. A discharge mechanism for carburetors comprising a casing secured inthe discharge chamber, a discharge orifice on said casing, a valve forengagement with saidorifice, means to support the valve in asubstantially balanced closed position, a valve stgin extended from saidvalve axially into said casing, an abutment hold- ""er adjustablysecured into said casing, an abut-- ment slidably' held in said holderso as to abut said valve stem, and resiliently yieldable means to urgesaid abutment against the stem so as to offset thebalance of said valvesupporting means and hold the valve open to an opening determined by theposition of said abutment, and means automatically to close said valveagainst the aciralilcgi of said abutment when the engine is not rung.18. A discharge mechanism for carburetors comprising a casing secured inthe discharge chamber, a discharge orifice on said casing, a valve forengagement with said orifice, means to support the valve stem extendedfrom said valve axially into said casing, an abutment holder adjustablysecured into said casing, an abutment slidably held in said holder so asto abut said valve stem, resiliently yieldable means to urge saidabutment against the stem so as tooffset the balance of said valvesupporting means and hold chamber, an intake regulating chamber, adischarge regulating chamber, said expansion chamber and said intakeregulating chambers communicating with each other so as to containxsubstantially equalized pressure, the pressure in said dischargeregulating chamber being controlled by the suction at the fuel dischargeorifice of the carburetor; a' diaphragm actuated fuel intake controlmechanism in said intake regulating chamber including a diaphragmresponsive to the pressure in said intake regulating chamber, and anelement extending to the outside of said intake regulating chamber tocontrol the fuel intake'of said expansion chamber; and a dischargecontrol mechanism including a diaphragm in said discharge controlchamber to operate said discharge control mechanism in accordance withthe suction at the discharge orifice.

20. A carburetor comprising an expansion chamber, an intake regulatingchamber, a discharge regulating chamber, said expansion chamber and'saidintake regulating chamber communicating with each other so as to containsubstantially equalized pressure, the pressure in said dischargeregulating chamber being controlled by the suction at the fuel dischargeorifice of the carburetor; a diaphragm actuated fuel intake controlmechanism in said intake regulating chamber including a diaphragmresponsive to the pressure in said intake regulating chamher, and anelement extending to the outside of said intake regulating chamber tocontrol the fuel intake of said expansion chamber, a discharge controlmechanism including a diaphragm in said discharge control chamber tooperate said discharge control mechanism in accordance with the suctionat the discharge orifice, releasable means to lock said dischargecontrol mechanism in a position to close the discharge orifice, and asecond diaphragm in the discharge control chamber acted upon by themanifold suction of the engine so as to release said locking means.

21. A carburetor comprising, an expansion chamber, an intake regulatingchamber, a discharge regulating chamber, said expansion chamber and saidintake regulating chamber communicating with each other so as to containsubstantially equalized pressure, the pressure in said dischargeregulating chamber being controlled by the suction at the fuel dischargeoriilce of the carburetor; a diaphragm actuated fuel intake controlmechanism in said intake re ulating chamber including a diaphragmresponsive to the pressure in said intake r ating chamber, and anelement extending to the outside of said intake regulating chamber tocontrol the fuel intake of said expansion chamber; a discharge controlmechanism including a diaphragm in said discharge control chamber tooperate said discharge control mechanism in accordance with the suctionat the discharge orifice, releasable means to lock said dischargecontrol mechanism in a position to close the discharge orifice, a seconddiaphragm in the discharge control chamber acted upon by the manifoldsuction of the engine so as to release said locking means, a heatexchange member in said expansion chamber, an inlet for the heatingmedium for said heat exchange member being adjacent to the intakeregulating chamber and to the fuel intake of the expansion chamber.

ROBERT L. DICKSON.

